Crystal Me vs Quantum Mechanics Notes
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Crystal Me
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This is an app designed specifically for crystal enthusiasts and beginners, aimed at helping you explore the charm of crystals and easily choose the ones that suit you best. Whether you are just starting your journey with crystals or are already an experienced collector, Crystal Encyclopedia provides a wealth of information. We have carefully compiled a wide range of knowledge about crystals, including their types, properties, and how to select them, helping you uncover the mysteries behind these natural treasures. Having trouble deciding? Don’t worry! Based on your Five Elements, chakras, zodiac sign, or Chinese zodiac, we help you find the crystals that suit you best—so you can make every choice with confidence. Crystals are not only beautiful decorations, but also a source of natural energy. Let the Crystal Me APP be your perfect companion in exploring the world of crystals, helping you find calm and strength in your busy life. If you encounter any issues while using the app, feel free to contact us at any time: 527291546@qq.com 411090877@qq.com
Quantum Mechanics Notes
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Quantum Mechanics Notes — a complete quantum mechanics study system in your pocket. WHAT THIS IS An original, systematic library of quantum mechanics study notes — 47 articles organized into six parts along a natural learning path: 1. Quantum Behavior & Foundations — double-slit interference, wave-particle duality, uncertainty relations 2. Formalism & Mathematical Structure — Hilbert space, operators, the Schrödinger equation, path integrals 3. Many Bodies, Symmetry & Condensed Matter — identical particles, atoms and molecules, band theory, superconductivity, the quantum Hall effect 4. Quantum Information & Quantum Optics — entanglement, teleportation, quantum computing, field quantization 5. Relativistic Theory & Frontiers — the Klein-Gordon equation, the Dirac equation, quantum field theory, quantum gravity 6. Gems & Minerals Special Topics — crystal field theory, color centers, spectroscopy, first-principles methods HIGHLIGHTS · 6,200+ LaTeX formulas individually typeset — a reading experience close to a printed textbook · 92 numerical simulation figures (interference buildup, band structure, decoherence dynamics, and more), each backed by a viewable Python script · Everything works fully offline — no network needed, perfect for commutes, labs, and exam week · Built-in LaTeX renderer: type or paste any formula and see it rendered instantly, with full-screen display · Import your own Markdown notes and photo albums, and bind them to the articles you are reading · Reading progress, table-of-contents navigation, dark and light themes PLEASE NOTE The notes are written in Simplified Chinese, and the app interface is in Chinese as well. Formulas, figures, and structure can be followed without Chinese, but the prose is not translated. COMPLETELY FREE The app is free with no ads, no paywalls, and no account required. "Support the Author" in Settings is an optional tip that unlocks nothing — all 47 articles are free for everyone, forever. WHO IT'S FOR Physics students preparing for exams or graduate-school entrance tests, researchers who need a quick formula reference, and self-learners who want a systematic understanding of quantum mechanics. Each article's mathematical level is labeled (L1 conceptual to L4 frontier), so you can choose your own starting point.
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Verdict
The clearest difference is update cadence: Quantum Mechanics Notes at daily against Crystal Me's every 5 days. Crystal Me's advantage is iOS requirement (15.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Crystal Me sells 1 one-off in-app purchase and Quantum Mechanics Notes sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
Crystal Me ships an update every 5 days, Quantum Mechanics Notes daily. The most recent releases landed on October 11, 2026 and October 3, 2026 respectively.
| Parameter | Crystal Me | Quantum Mechanics Notes |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 5 days | Daily — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 159 MB | 32 MB |
| Age rating | 4+ | 4+ |
| Developer | 梦琦 徐 | 际 郭 |
In-app purchases
Crystal Me
- 水晶Crystal Pro$0.99
Quantum Mechanics Notes
- 支持作者 ¥6$0.99
- 支持作者 ¥1$0.99
- 支持作者 ¥8$0.99
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- 支持作者 ¥28$3.99




